Red-violet vat dye and process of making same.



UN T D STATES PATENT OFFICE.

ALBRECHT SCHMIDT. AND \l'IL-llELM. BER'FRAM, OF HOG-ll-ST-ON-Tlll firl.tiN, Q'ERMA NY,

' ASSIGNORS TO IFARlHYERKE VORM. MlClSTEIt LUUIUS & BRUNlM t)! H00HST-ON- TI-IE-VAIN, GERMAN Y, A CORPORATION OF i1CR-M1XN1 RED-VIOLET VAT DYE AND PROCESS OF MAKING 5 To all 'whom it may concern:

,Main, Germany, have invented certain new and useful Improvements in the Process of Making Red-Violet Vat Dyestuffs, of which the following is a specification. We have found that on heating dihalogen-thiogly- (.(Jlll(Z-Uft-l\U CiLl'bOXyllC acids with bisullite solutions at temperatures above 150 C underpressure, vat dyestuffs are formed which dye cotton and wool a hydrosultite vat, for instance, red violet tints.

The. process may be carried out, for instance, as follows: I Example L, The dyestull' [rout dichlorophenylthioglycollhe-ortlui-carboxylic acid COOH 1 (Ol )C,-,H I

scmoooH 2 (Amtalrrn r1. Chem/0 2T-l,2ll'), obtained by the dichlorination ol' ortho-acct toluidids, is oxidized, for instance,

into lichloi'ophenylthioglycollic-orlbo-czirboxylic acid. liy n1ezins ol" cliloroacctlc acid in alkaline solution.

The transiornmt ion of this diehionvphenylthioglycollicorllio-earboxylic acid into the dyestul'lis carried out, by heating, for instance, parts by weight. ot' the acid in a (ZlUNXlVL'EfiL'l to 'l7U-lt t| t.- for about 3 hours, prelcl'ably while stirring, with about 250 parts by weight.

, ol" comnierical t't'mcentratcd sodium bisultite solution.

. dilute soda-lye, whereupon the dyestull remains be-- (oi about l-(l ei centstrongl-h). The. roduct ol'. reuclion, consisting of a violet black mass is boiled with hind, The dyestul't', when treated withan alkaline hydrosullitc solution becomes dissolved as louco compound and dyes from this wool and cotton in red vio- Specification of Letters Patent. 4 Application filed January Z2, 1907. Serial No- 353,528.

imen'ted Oct. 8 1907;

lot tints. The dyestufl is a violet black powder, soluble with'great difiiculty in concentrated sulfuric acid .with a. green, in hot nitrobenzene with a red violet color, producing on porcelain a violet black metallic stroke.

Example II. A dyestuff may also be obtained, for instance, fiom dichlorophenylthioglyciill'ic-ortho-carboxylic acid, ioimed-in the aforesaid manner, from dichloroanthranilic acid, obtained by dichlerination of anthranilie acid or aeetarithranilic acid in acetic acich The dyestufi is also aiyiolet black powder and dyes cotton and wool in the vat in red violet tints. J

Example III. Dyestufl' from 'dibromophenyltliioglycollic-ortho-carb'oxylie acid. The'clibromophenylthi0 glycollic ortho-carboxylic acid may be obtained according to the method described in Example 1 from dibromoacet-ortho-toluidid' (Annalc'n 168, 187) or, for instance, from dibromo-anthranilic acid obtained by the (librolnination of anthranilic acid or by the dibroniinatien of ortho-nitrotoluene. 3, parts byweight oi dibroinophenylthioglyeollic-ortho-carboxylic acid are heated in a closed vessel to.l70-180 C or about 3 hours with about l5- parts by weight of a commercial concentrated sodium bisullite solution (of about 40 per cent, strength). The vi0let black'crystalline mass is boiled. with dilute soda-dye, whereupon the dyestutf remains behind. it dyes in the vat, like the dyestuli t'roni dichloropliellyltliioglycollie o1'tho carboxylie acid, cotton a red violet.

Having now ghacribed our invention, what we claim is:-

i. the process herein described for making rediviolet vut dyestulis, which consists in heating dlluiIogen-Lhiogly ollie-orthu-carboxylic acids ivith bisultites.

2. As new product, the l'i'il violet dyestutl) obtained from I diehloro-phenyltliiogtyeollie-m'tlio-curboxylie acid. soul ilyestull being ziviolet black powder, very llll' l'n'ultly soluble "in concentrated sulfuric :ieitlwith :1. green,

inhot uitrolsonzene with a red violet color and Moducil on porcelain :1 violet: black metallic stroke.

1n te, -l.inlou,\', that; we (tlglihLlillt: lfol'egoiug as our invention. u'oluive signediour names in presence of two Hulk scribing witnesses.

' ALl'vlil'lCll'l? SPUMIU'I.

WlI'JlUGLM BIGR'LRA M.

Witnesses:

411mb; GRUND, GART; Genus. 

